Food freezing tunnel



June 21, 1949. A. SILVERA 2,474,069

FOOD FREEZING TUNNEL Filed March 16, 1945 FlG.l

- INVEN TOR. 2 BY Patented June 21, 1949 FOOD'FREEZING 'TUNNEL -Americo-Silve1-a; Syracuse,'.N. Y.,-ass ign0r. to Carrier Corporation,v Syracuse, N. Y.,.a. corporation of Delaware Application Mar'ch 16, 1945, Serial No. 583,125

(Cl.l62102) 3 Claims. 1 This invention relates to methods of and means for. freezing :food and other products.

The general object of the invention is to :p-rovide a simple, economical, and highly flexible .systemof freezing products of 'diiierent'kinds,

more Y particularl food products, employing a minimum of: equipment, adapted to be variously arranged to suitta plurality of different freezing needs.

-A feature'of the invention resides in the provision-cf-a series of units, arranged to be'posi- .tioned to form-a multistep freezing system. *Each .unit may be in the nature of a self contained apparatus, while the combination of-axplurality-gof .units, individually controlled to produce and maintain desired temperature conditions, results in a complete system for handling almost every type of food :produce requiring freezing.

. Another. feature of the invention consistsinthe arrangements of unitary apparatus in combination with the distribution-of air supplied bysuch apparatus-so-that'an area, in the'nature of a tunnel, is provided for housing a rack or truckcontaining produce to; be frozen. By juxtapositioning aplurality of such units a tunnelof desired lengthis provided. Since-each of the units may .beoperated to provide a predetermined condition, the movement of a truck through the tunnel Wi1l subject the-produce thereon to a series of-air conditions, as "ma be desired, in order best--to' promote the freezing-operation.

Another feature ofthe invention-resides -in'-.-the use of substantially standard cold diffuser equipment arranged most economically to recirculate .airina substantially closed. circuit. 'Airdistributionmeansassurethe routing. of suchair through produce positioned in the path of their vmovement.

A furtherflfeature covers the use ofair conditionedby such apparatus in a storage area served by. the apparatus, apart from the area within the apparatusemployed primarily for produce freezmg.

Anothenfeature covers the positioning of circulating units in side by side crelationship .so that theimovement of air in one unit will be in a direction opposite to that in the other unit-With the resultthat produce conveyed through-a series .of such .units will .be .uniformlyltreated and the produce. frozen equably throughout.

These. and other features will bemoreapparent from the. following description of one: form of the inventionsto be. readinconnection with the accompanyingdrawing, in which v Fig.1 .is a diagrammatic. illustration, .partly =-in-plan andpart-l in section of 'myarrange- -ment;

-Fig. iscz-a diagrammatic view, in sectionpon the lines 2--2:-of Fig. 1.

Considering the drawing, similar'designations referring a to similar :parts, numeral 3 generally "designates-a freezer :arrangernentincluding-innit enclosures'=4 536,1,:i B and 9. 'it x-will be eapparsent that salthoughsix unit enclosuresare'illusxtra-ted nany nnmberamay :be emplcyedgdependsingupon the-:use to which my "system' will beaput. Ante-rooms 0 land:- I I are-positioned at'botn ends of the series of=unit-;enclosures, as-shownirr'l ig. .-1. Although. the-enclosures may" be individually .constructed, sand separable, min some instances it may-.- be:-desirable to "have the wall and ceiling elements joined together: in' Y a: continuous permanent r s-tructu-ral arrangement. For purposes :of the-invention; it will-'be'con'sidered: t'hatceach" of -the @enolosures sand ante-rooms is a -separate .-unit .Whichmay '.be shifted as desired so that itheiarrangement maybe-shortened on 'lengthene'd -depending .upon different requirements. :It will [be understood the variousaindividual unitsmay be connected together by'sanyfasuitablefmeansgilf -desired, Whenathey aredisposed in juxtaposition (to-one another, and;jpreferably,aare sealed to-sep- .arate.the;passageways-provided thereby from the surrounding area.

Ante-room loiszprovided with doors- 1 2 through .Which food: conveyortrucks fa are admitted. to the -..ante+room. .FPrucks l as shown in, Eig.;a2, aresprovided with trolley wheels i t adapted .to run ions-rails: t5 ;-.each= truck l3sis equipped with a guide iandwtowraattachment :16, which maybe in 'the form of a conveyor attachment "or otherwise, :adapted; to=.engage= the" spr0cket' chain. of arconventional.conveyer;21;-:conv eyer 21, may besuit- -.ably nactuated by any 5 desired'ineans. Attach- .ments i 1.6 esecure the-in ucks 3'13 to: conveyorf2'l; :movement' of conveyordl. moves .aeach truck t3 .f'romwonevend iof arrangement to the other, .emergingiat the iaraend'throughzdcors l'l. Each ,of: theuunit :enclosures 4 .9- is equipped with-24a :cold azdifliuser l8, ypreferably in self-contained iunitaryeform. The coldzxdiifusen equipment invacludes ea :refrigerantucoil: housing l9: containing a one oramores rows;of--;coil==surface in which: refrigerantradapteditobe expanded therein, is supzpliedprfrom sa .tcentral refrigeration r:system,:.-not ashown. Ain leaving housingvil9' is.-;ats.-a desirable .low temperature;depending upon the refrigera- ..tion controls employed andeassuming, of course, that t-adequate lrefrigeration t'capacity ":is zeailaliltable. Thisiain-enters'fansZ0; driven'zbyzmotorfll mounted on the side of the unit enclosure, through a suitable drive. The air is discharged into distributing duct 22 within which are positioned, if desired, flow vanes 23 for assuring equal distribution of the air throughout different portions of the supply duct. The air is delivered to the opposite end of the enclosure, into a plenum chamber 2% one side of which is equipped with difiusion grilles 25. The diffusion grilles serve to distribute the air substantially uniforml over the whole discharge area from plenum chamber 24 with the result that every rack in food conveyor 13 positioned within the unit is subjected to a flow of air therethrough which is then returned for reconditioning through intake grille 26. Thus, a compact recirculating system is provided, with a minimum flow path, so that losses due to dissipation are held to a negligible percentage. The air leaving the cold diffuser is delivered substantially at its discharge temperature to th produce on the food truck. In this case, it should be noted that motor 2i for driving the fan 20, is located outside the unit so that the heat generated therefrom will not be imparted to the air stream.

The rate of advance of a series of food trucks through the tunnel freezer arrangement 3 formed by the combination of unit enclosures 4--9 may be suitably controlled. Thus, the towing of food conveyor trucks may be on an intermittent time schedule with a pre-determined period of time in each enclosure, or a slow moving continuous passage may be provided.

The cold diffuser in unit 4 delivers air in the direction shown by the arrows while the air discharged in unit flows in the opposite direction; and similarly a reversal in flow is provided in alternate units. In consequence, the produce on conveyor trucks will not have one end continuously subjected to the first impact of conditioned air but instead will have the opposite ends alternately subjected to the first flow of air thus assuring greater uniformity in the treatment of the produce, regardless of position on the racks of the trucks.

Each unit enclosure has an entrance 28 suitably equipped with doors 29 so that a service man may readily enter each enclosure for inspection and repair.

In practice, one or more trucks will be admitted through doors l2, assuming the direction of travel is from left to right, as indicated by the broken arrow in the illustrated arrangement. After entering ante-room II], the trucks will pass through doors 3% and assume a position in the tunnel area within unit 4.

Assuming quick freezing action of produce is desired, air at a temperature on the order of -40 F. will be supplied by fan 2!), and such low temperature air will be rapidly circulated to the produce on trucks 13 as shown by the arrows in Fig. 2. Speedy freezing to desirable low temperature will thus be achieved at a rapid rate to avoid the formation of undesirable large crystals. After a suitable interval, the trucks from enclosure 4 will move into enclosure 5 and there be subjected to a rapid circulation of air delivered at a predetermined temperature, say 30 F. delivered in enclosure 5 need not be as low as that delivered in enclosure 4 since the essential quick freezing will have progressed to the point where a somewhat higher temperature may satisfactorily be used in this second step for producing an interior frozen condition on the order In particular, the temperature of air.

4 of zero to 10 F. which is an acceptable storage range for most products.

As the trucks proceed through units 5, I, 8 and 9 the temperature of the air delivered in each enclosure may be set to assure a final frozen condition of the produce required for optimum storage. This condition is reached in enclosure 9 whereupon the trucks proceed into exit anteroom I! through doors 3i and then emerge into the area beyond exit doors II.

If desired, applicants tunnel arrangement may be positioned within a larger storage area so that in practice the trucks after emerging from the tunnel may be unloaded directly within the storage area without subjecting the produce to any intervening temperature higher than that desired for good storage. To this end, applicant provides hinged portion 33 shown in Fig. 2. By swinging said hinged portion or section about pivot 34, it will be brought to rest against the side of the unit enclosure with damper 35 in cutoff position 36 so that the air then delivered by the cold diffuser will be discharged into the storage area surrounding the unit.

The use of individual cold diifusers in each separate unit enclosure enables each coil section to be separately defrosted without regard to the coil sections in other units.

Thus, for example, the coil of unit 9 may be defrosted by the use of water, brine, hot gas, or other method, Without in any way interfering with the operation of the cold diffusers in the other units. This enables substantially continuous operation since it is possible to carry on different stages of th freezing operation at all times even though one or more units require defrosting and are removed from service.

The same applies to cases in which a breakdown of one unit occurs. If the operation of one unit is impaired the other units will continue to operate, the only variation occurring in the length of stay of the food truck in the units left operating.

While the structural details of the units and their interpositioning form no part of the invention, it will be understood that suitable insulated wall structures, and methods of connecting together of units, sealing the same to assure airtightness, proper provision for truck guiding and towing, etc., will suggest themselves to those skilled in the art. Since such details of design and modification of parts may be employed without departing from the spirit of the invention, it is intended that no limitations be read into the invention or the scope thereof except such as are definitely included in the appended claims.

I claim:

1. In a combination of apparatus of the character described, an enclosure, said enclosure having a door, ceiling and sides, means disposed at one side of the enclosure housing a cold diffusing apparatus, a distributing duct adjacent the ceiling area for conveying air from the cold diffuser apparatus, a plenum at a side of the enclosure opposite the cold diffuser apparatus, one of the sides of the enclosure forming a side of the plenum, a diffuser grille forming the opposite side of the plenum diifusing air from the plenum into thearea formed by said apparatus, duct and plenum, said area constituting a tunnel, and means for conveying food to be frozen through said tunnel.

2. In a system for freezing materials, the combination of a plurality of freezing units, each unit having a passageway therethrough, the series of passageways forming a tunnel, each unit having a floor, ceiling and sides and including means disposed at one side of each unit housing separate cold diiiusing apparatus, a distributing duct adjacent the ceiling area of each unit for conveying air from the cold diflusing apparatus, a plenum chamber at a side of each unit opposite the cold diffusing apparatus, means for diffusing air from the plenum chamber into the area formed by the cold difiusing apparatus, duct and chamber, means for conveying food to be frozen through the tunnel and means for disposing a section of a unit so that in a first position air from the difiusing apparatus will be routed to the tunnel and then to the coil of the diflfuser while in a second position air from the cold diffuser will be routed to an area surrounding the system for cooling the same.

3. In a system for freezing foods, the combination of a series of separate, self-contained cooling units in juxtaposition with respect to one another, and each unit having a passageway therethrough, the series of passageways forming a continuous tunnel, each of said units being adapted to supply air at a desired low temperature within a portion of the tunnel and including means disposed at one side of each unit housing separate cold diffusing apparatus, a plenum at REFERENCES CITED The following referenlces are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,930,414 Buhr Oct. 10, 1933 2,136,969 Downey Nov. 15, 1938 2,237,256 Finnegan Apr. 1, 1941 2,237,257 Finnegan Apr. 1, 1941 2,265,858 Reynoldson Dec. 9, 1941 2,300,229 Knowles a Oct. 27, 1942 2,382,084 Mathews Aug. 14, 1945 

